101639521 has 4 divisors (see below), whose sum is σ = 103802112. Its totient is φ = 99476932.

The previous prime is 101639491. The next prime is 101639539. The reversal of 101639521 is 125936101.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 101639521 - 2¹³ = 101631329 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 101639521.

It is not an unprimeable number, because it can be changed into a prime (101639561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1081225 + ... + 1081318.

It is an arithmetic number, because the mean of its divisors is an integer number (25950528).

Almost surely, 2^101639521 is an apocalyptic number.

It is an amenable number.

101639521 is a deficient number, since it is larger than the sum of its proper divisors (2162591).

101639521 is an equidigital number, since it uses as much as digits as its factorization.

101639521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2162590.

The product of its (nonzero) digits is 1620, while the sum is 28.

The square root of 101639521 is about 10081.6427728818. The cubic root of 101639521 is about 466.6818060281.

The spelling of 101639521 in words is "one hundred one million, six hundred thirty-nine thousand, five hundred twenty-one".